The completion of the human genome project, the creation of unique genetic research resources, and the development of robust genome analysis technology, have provided powerful tools to unravel the genetic contribution to health and disease. Yet, many human diseases are the product of complex interactions between genes and environment. The NHGRI and government advisors have identified the creation of a U.S. longitudinal study to collect environmental exposures, genetic risk factors, lifestyle, and medical experiences from hundreds of thousands of Americans as uniquely valuable. Politically, a study of such enormity and consequence requires that the public support - or at least not actively oppose - its undertaking. Ethically, such a study should be designed and undertaken in cooperation with citizens, after the hopes and concerns of ordinary citizens are sought, duly considered, and addressed. The goal of this proposal is to obtain wide societal input to inform the design and implementation of a possible large U.S.-based longitudinal cohort study of the role of genes and environment in health and disease. The project has three specific aims: 1) Develop and evaluate informational materials describing the goals and design considerations of the large cohort study; 2) Assess public attitudes about the proposed cohort study at the individual level; and 3) Engage citizens and community leaders to assess attitudes and pilot test methods of initiating community-based dalogue. This pilot project will use qualitative and quantitative methods to provide a rich and representative assessment of the public's attitudes and to engage the public in an initial dialogue about a possible large cohort study. The pilot will be conducted in five geographically and demographically distinct locations, as well as nationally using a representative sample. The project will explore specific study design elements and the perceived benefits and risks to participants, communities, and society; engage community leaders; evaluate methods of stimulating citizen dialogue and public consultation; and convene a citizens' advisory panel to provide guidance and assess the effectiveness of these methods for a large cohort study.